Advice on lactose intolerance from Dr Joanna Longstaffe

I CONSIDER myself to be pretty healthy and am within the recommended weight for my height and yet I almost constantly feel bloated to the point where my clothes have become uncomfortable even though my physical weight remains the same.

I CONSIDER myself to be pretty healthy and am within the recommended weight for my height and yet I almost constantly feel bloated to the point where my clothes have become uncomfortable even though my physical weight remains the same. I have also been experiencing diarrhoea and stomach pains. On the advice of a friend who’s a nurse I have started keeping a food diary and the only consistent item seems to be milk – could you explain a bit more about lactose intolerance?

Lactose intolerance is a digestive problem defined by the inability to digest lactose, a sugar mainly found in milk and dairy products, and other foodstuffs including bread and baked goods, and also cereals. It is much more common than people may think.

Lactose can only be absorbed by the body if it is correctly broken down into glucose and galactose. In those with intolerance to the substance, it cannot be broken down and therefore is not absorbed into the bloodstream – this causes the unpleasant symptoms associated with the condition.

Some people may be born with a tendency to develop lactose intolerance whereas others are found to develop the disorder over time.

Symptoms associated with lactose intolerance include as you’ve mentioned, bloating, stomach pain, flatulence and diarrhoea – and these can become apparent anytime between 30 minutes and two hours after consumption of the offending product. The severity of these symptoms will usually depend on the amount of lactose that is consumed.

Keeping a food diary of the food and drink you consume is an excellent way to keep an eye on what you’re putting into your body and what effect it is having. If there are any clear patterns, as you seem to have found with milk, then you should make an appointment with your local GP for further testing. You may be asked to remove milk and other dairy products from your diet for two weeks to assess the impact this has on your symptoms.

If the results of the initial tests are unclear, your GP may advise additional testing. This could include a hydrogen breath test which involves fasting overnight and then consuming some lactose – if a large amount of hydrogen is present then lactose intolerance is diagnosed.

In some cases blood tests may also be required to detect the amount of glucose in the blood after eating or drinking lactose.

Those with lactose intolerance often worry they will not get enough calcium in their diets; however, there are a number of other food items which can replace dairy products. Good sources of calcium include salmon and other oily fish and also dark green leafy vegetables such as broccoli, spinach and kale.

There is no cure for the disorder but if you are diagnosed with lactose intolerance there are many lactose free products readily available in most supermarkets now, including dairy free milk, so choices are nowhere near as limited as they were just a few years ago.